The shearing action of blade-type cutters often causes thin-walled cylindrical structures to be substantially deformed adjacent to the cut. In an attempt to prevent deformation of resilient structures and thereby gain an improved cut, blades with piercing points are used. Blades such as these are disclosed in U.S. Pat. No. 2,870,538 issued to Townshend on Jan. 27, 1959, U.S. Pat. No. 4,412,380 issued to Kish on Nov. 1, 1983 and U.S. Pat. No. 4,845,849 issued to Aubriot on Jul. 11, 1989. While the disclosed cutters provide an improved cut to resilient structures, these cutters still cause thin-walled, less resilient structures to be deformed.
Blade-type cutters with piercing points for use in cutting thin walled structures have been disclosed. U.S. Pat. No. 4,549,349 to Harrison issued Oct. 29, 1985 discloses a blade-type cutter having a piercing point. The cutting of thin-walled structures is enhanced by this blade however the final severed structure is partially flattened.
A blade is disclosed herein which cuts cylindrical structures without substantially deforming the wall curvature of the structure adjacent to the cut.